Monochamus alternatus and M. saltuarius were reported as the vectors of Bursaphelenchus xylophilus, pine wood nematode in Korea. According to Kwon et al. (2006), each of 2 species has occupied their own regional distribution : M. saltuarius in southern part including Jeju island and M. alternatus in mid-northern part of Korean peninsula. We measured the supercooling point (SCP) of 2 species (laboratory-reared populations) by each of developmental stages. The SCPs of 2nd, 3rd and 5th instar larvae of M. saltuarius were -7.68±0.19℃, -7.02±0.69℃, -4.93±1.34℃ each of stages. On the other hand, the SCPs of 3rd, 4th, 5th instar larvae and pupae of M. alternatus. were -4.46±1.12℃, -5.94±1.33℃, -7.83±1.44℃, -9.53±1.78℃ each of stages. The SCPs of M. saltuarius larvae generally was lower than that of M. alternatus. The pupae of M. alternatus and 2nd instar larvae of M. saltuarius had the lowest SCP among measured samples. On the other hand, the highest SCP were recorded in 2nd and 5th instar larvae, each. This result shows that regional distribution of 2 beetles may be associated with the adaptation capacity to low temperature represented by the SCP as well as the developmental temperature. However, beetles experimented were not collected from pine forest fields. In further study, we are planning experiments with field populations and all developmental stages.

A cDNA of PBAN receptor (Plx-PBANR) isolated from female pheromone gland of the diamondback moth encodes 338 amino acids and has 7 transmembranes, belonging to G-protein coupled receptor family. The fact that Plx-PBANR expression was only found in female pheromone gland revealed that pheromone gland is the only molecular target of Plx-PBAN. Plx-PBANR expressing cells increased level of Ca2+ influx when challenged with PBANs. When RNAi fragment for PBANR was injected into pupae, suppression of PBANR expression was maintained for at least 2 days at post-emergence. Injection of RNA fragment for inhibition of Plx-PBANR expression also inhibited mating behavior and suppressed sex pheromone production, suggesting that some molecular target was affected by reduced Plx-PBANR expression. We cloned partial Δ9 and Δ11 desaturase gene and investigated expression level in Plx-PBANR-RNAi moth. It is of interest that desaturases expression was reduced by RNA fragment injection. These results suggest of PBANR expression affects the molecular biological events of PBAN and eventually suppresses mating behavior.

This study was performed to analyze the sugar contents from six kinds of plant and investigate their effect on the life span of ggot-mae-mi, Lycorma delicatula. Part of plants were methanol extracted from host plants such as Ailanthus altissima, Vitis vinifera and non-host plants such as Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora, and concentrated the water layer and then analyzed the sugar contents using HPLC. Ailanthus altissima existed high in sugar contents and followed by Fructose>Glucose, Vitis vinifera was analyzed by an order of Glucose>Fructose>Maltose>Sucrose>Rhamnose; Malus pumila was as Glucose>Fructose; Pyrus calleryana was as Glucose>Unknown>Fructose; Hibiscus syriacus was as Sucrose>Glucose; Pinus densiflora was as Fructose>Glucose>Sucrose. A parafilm bioassay was used to investigate the longevity of L. delicatula nymphs to the sugar contents. Nymphs of L. delicatula was lived as long as 13.1 days in 5% Sucrose solution, but lived as short as 6.0 days in 5% Glucose solution. When provided with only water, L. delicatula lived for 5.4 days. Life span to the each sugar contents were longer lived in an order of Sucrose>Fructose>Rhamnose>Maltose>Glucose. As investigated the life span of L. delicatula nymph according to the combination of sugar contents founded in original plants were lived longer in 5% sugar combination solution of Ailanthus altissima. Analyzed original sugar contents from Malus pumila, Pyrus calleryana, L. delicatula was lived as 7.8, and 7.1 days, respectively, comparing to the Hibiscus syriacus, and Pinus densiflora lived as 6.0, and 4.7 days, respectively. This result were judged that sugar contents affected on choosing the host plants.

This study was performed to compare the host preference, survivorship and feeding behavior using EPG against ggot-mae-mi, Lycorma delicatula against seven plants such as Ailanthus altissima, Vitis vinifera, Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora. In host preference. L. delicatula was most preferred the Ailanthus altissima, Vitis vinifera and was not preferred the other plants. Survival rate of 3rd Nymph was recorded from Ailanthus altissima, Vitis vinifera as 15.0, and 15.4 days, respectively, it showed longest period. However, Malus pumila, Pyrus calleryana, Hibiscus syriacus, were survived within 6 days and Pinus densiflora was within 5 days. Moreover, L. delicatula was survived within 2 days to the three kinds of fruits. Ecdysis rate from 3rd to 4th nymph also high from Ailanthus altissima, Vitis vinifera as 63.3, 63.0 % and the order was followed as Malus pumila(17.7%) > Pyrus calleryana(9.3%) > Hibiscus syriacus(7.8%) > Pinus densiflora(5.9%). Especially, ecdysis rate was recorded 0% to the three kinds of fruits. Feeding behavior was analyzed using EPG and compared the differences their waveform from seven kinds of plants and three kinds of fruits. Non-probing time was short in host plants, reversely, Phloem-feeding time was recorded longer in Ailanthus altissima, Vitis vinifera as 45.7 and 13.7 min, respectively. And other plants and fruits were not showed feeding behavior.

This study was performed to investigate the correlation between changes of feeding behavior of green peach aphid, Myzus persicae and residual effect of an insecticide, Pyrifluzuinazon, using EPG technique. Pyrifluquinazon was showed the insecticidal activity until three days (72h) after treatment, and the activity was high in nymph than adult of GPA. There was no difference among treatment methods. Lethal sign was observed the slimed the abdomen of GPA after 3 days that rises the insecticidal activity, and dieㅇ as being sticked and/or pulled out the needle. Residual efficacy from 1, 3, 5, 7 to 20 days after treatment, insecticidal activity was showed 70% in 50 ppm, recommended concentration, until 5 days. And waveforms relating to non-probe time and phloem phase time using EPA, feeding inhibition efficacy was showed during 5 days after treatment, but showed similar level with control after 13 days. These results show that the change of feeding behavior of GPA is correlated with the change of residual effect of pyrifluzuinazon.

In order to understand the nature of population genetic structure of the notorious pest insect, Spodoptera litura (Lepidoptera: Noctuidae), a total of 159 individuals of the tobacco cutworm collected from six Korean and five Chinese localities were cloned and sequenced their mitochondrial A+T-rich region. A total of 90 haplotypes ranged 324 bp ~ 372 bp in length and 0.30% ~ 4.85% in sequence divergence. Compared to the preliminary mitochondrial COI gene sequence data that provided nearly identical sequences in all samples, the A+T-rich region provided substantially high sequence variation, validating the applicability of this molecule to the study of intraspecific variation. Overall, a very high per generation migration ratio (Nm = 5.91 ~ infinite), a very low level of genetic fixation (FST = 0 ~ 0.077796), and no discernable isolated population were noted to exist among populations of S. litura, although some significant genetic differentiations were found between several pairs of populations. These results collectively suggest that the S. litura populations in both Korea and China are very well interrelated to each other. The structural analysis revealed that the S. litura A+T-rich region harbored two stretches of the [TA(A)]n sequence, the poly-A stretch, and a stem-and-loop structure that are well found in other lepidopteran A+T-rich region. Furthermore, the region harbors the 13 ~ 19-bp long T stretch and 5-bp long motif that have been suggested to function as a possible recognition site for the initiation of replication of the minor strand of mtDNA also were found.

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is one of the most notably utilized for greenhouse pollination in Korea. In order to understand the nature of genetic relationships, gene flow, and population structure of the species we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to “animal barcode” region and the complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (nrDNA) with the individuals collected from Korean localities. Although the 658-bp long mtDNA sequence provided only six haplotypes with the maximum sequence divergence of 0.456% (3 bp, from 91 individuals), but the ITS sequences provided 33 sequence types with the maximum sequence divergence of 0.78% (16 bp, from 35 individuals), confirming better applicability of the ITS sequences to the study of intraspecific variation. The ITS2 sequences of B. ignitus were shown to be the longest among known insects, ranging in size from 2,034 bp ~ 2,045 bp and harbored two duplicated repeats, indicating unusual structure of B. ignitus ITS2 sequences compared with other insect ITS sequences. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population/population group were noted to exist among populations of B. ignitus on the basis of both molecules, thus suggesting that the B. ignitus populations on the Korean peninsula are panmictic, which is consistent with our understanding of the dispersal capability.

Eumenis autonoe, a member of the lepidopteran family Nymphalidae (superfamily Papilionoidea) is an endangered species, and is found only on one isolated remote island, Jeju in South Korea, on Halla Mt., at altitudes higher than 1,400 meters. In this study, we report the complete mitochondrial genome (mitogenome) of E. autonoe. The 15,489-bp long E. autonoe genome evidenced the typical gene content found in animal mitogenomes, and harbors the gene arrangement identical to all other sequenced lepidopteran insects, which differs from the most common type found in insects, due to the movement of tRNAMet to a position 5’-upstream of tRNAIle. As has been observed in many other lepidopteran insects, no typical ATN codon for the COI gene is available. Thus, we also designated the CGA (arginine) found at the beginning of the COI gene as a lepidopteran COI starter, in accordance with previous suggestions. The 678-bp long A+T-rich region, which is second longest in sequenced lepidopteran insects, harbors 10 identical 27-bp long tandem repeats plus one 13-bp long incomplete final repeat. Such a repeat sequence has been, thus far, only rarely detected in lepidopteran mitogenomes. The E. autonoe A+T-rich region harbors a poly-T stretch of 19 bp and a conserved ATAGA motif located at the end of the region, which have been suggested to function as structural signals for minor-strand mtDNA replication.

Deciduous tree fruits such as pears and apples are widely grown in the Pacific Northwest of the United States and are well adapted to the seasonal environment in that region. Extended cold periods provide adequate chilling to break dormancy and reinitiate growth in the spring. Cold exposure synchronizes the physiological processes and makes sure that bloom is uniform and that fruit matures in a uniform manner. As a result of global warming, some fruit-growing areas may experience inadequate cold exposure during the winter months, gradually shifting the southern boundary for production of deciduous fruits further north. However, climate change will affect not only growth and fruiting habits of fruit trees but also the insect and mite pests which feed on them. There is general agreement that in temperate regions a trend towards warmer summers and milder winters will generally benefit insect and mite pests and increase their injuriousness. Temperature changes in particular will impact the development, mortality, phenology, and voltinism of fruit pests. Here we discuss how climate change may affect pests and control practices on deciduous tree fruits in the Hood River Valley of northern Oregon. This small valley extends in a north-south direction from the Columbia River to the foothills of Mt. Hood and is characterized by a varied topography and large altitudinal differences (sea level to 600 m). The major pest of pears and apples in that area is codling moth, Cydia pomonella L., a cosmopolitan pest which is present in most deciduous fruit-growing areas of the world. Like its host trees, the codling moth is well adapted to a seasonal environment. Diapause is the principal mechanism which synchronizes its phenology with the tree and the presence of fruit, the larval food source. Diapausing overwintering larvae require cold exposure (chilling) to terminate diapause in late winter or early spring. At the lower elevations close to the Columbia River the codling moth is bivoltine but gradually becomes univoltine at the higher elevations where the growing season is shorter and fewer heat units (above 10oC) are available for development. Long-term temperature records from the lower Hood River Valley indicate that the 25 years since 1985 have been considerable warmer than the 25 years prior to 1985. For instance, the average heat units available for codling moth development over a season have increased by more than 10% over the last 25 years. The codling moth is adapting to this warming trend by gradually increasing its voltinism (number of generations). As a result, the severity of codling moth as a pest can be expected to increase. Therefore, fruit growers will have to adjust and intensify control practices to keep fruit free from codling moth damage. We will also explore how other fruit and foliage feeding pests which are part of the pest complex of pears and apples in northern Oregon fare under different global warming scenarios compared to codling moth.